1. Field of the Invention
The present invention relates to an electronic musical instrument typified by an electronic keyboard instrument, such as an electronic piano or an electronic organ. The electronic musical instrument to which the present invention is applicable includes not only an electronic keyboard instrument, such as an electronic piano or an electronic organ, but also a musical instrument, such as an acoustic piano, a pipe organ, a cembalo or a celesta, which is provided with a keyboard and musical tone control operators. In recent years, more and more acoustic keyboard instruments have come to incorporate a performance recording and reproducing device and a performance assist device for giving a key-depressing instruction or the like, and the present invention is useful in mounting functional components which are large in thickness, such as control operating elements, in the interior of a fallboard.
2. Description of the Related Art
There has been proposed an electronic keyboard instrument of the above-mentioned kind, in which an operation panel having electric component parts forming operators arranged thereon for setting tone colors and other parameters is formed integrally on an inner surface of a fallboard (see Japanese Laid-Open Patent Publication No. S60-122989). In this electronic keyboard instrument, the operation panel functions as a fallboard, and therefore the operation panel pivotally supports the rear end of the fallboard on the body of the musical instrument so that during musical performance, various musical tone parameters can be set using the operators on the operation panel, with the fallboard being in an open state.
In this electronic keyboard instrument, since the fallboard is designed to function not only as a fallboard but also as an operation panel, the thickness thereof is inevitably increased. As a result, there is some distance between a surface of the keyboard and upper surfaces of loudspeakers disposed on the left and right sides of the keyboard, so that when the player is playing a musical composition having dynamic and quick passages with quick and large pitch changes, the player's hands or fingers sometimes hit side surfaces of the loudspeakers, which degrades the performance. This problem could be solved by increasing the width of each cheekblock, but this increases the whole width of the musical instrument.
Further, the above conventional electronic keyboard instrument has a pivotal motion support configured to have a large size so as to increase the rigidity of the support and ensure the stability of pivotal motion of the fallboard. Otherwise, the fallboard cannot be stable in its up or raised position. Furthermore, to hold the thick fallboard as it is in the up or raised position, a space for receiving the fallboard, corresponding to the thickness of the fallboard, has to be provided at the rear of the fallboard, which not only makes it impossible to design the electronic keyboard instrument compact in size, but also seriously spoils the appearance of the electronic keyboard instrument.
When an electronic keyboard instrument has a large-sized fallboard, a large force is required to open and close the fallboard, and safety at the start and end of opening and closing operations cannot be assured. One known solution to this problem is a construction in which divided parts of the fallboard are connected to each other. For example, there has been proposed an electronic keyboard instrument disclosed in Japanese Laid-Open Patent Publication No. H11-175053, which has a construction in which the fallboard pivotally moves and retreats when it is opened. In this electronic keyboard instrument, as shown in FIGS. 11A and 11B, the fallboard which extends substantially horizontally in its closed state is divided into a front cover 106a and a rear cover 106b, and the two covers 106a, 106b are connected by a hinge member 107. The front cover 106a has arms 108 extending downward from the respective opposite lateral side edges thereof at the rear end thereof, and the arms 108 are pivotally supported on a pivot 114a. The rear cover 106b has a rear end thereof slidably supported on manual cover guides 103. In this construction, to open the fallboard, the front cover 106a turns about the pivot 114a of the arms 108, and this motion of the front cover 106a causes a rearward sliding motion of the rear cover 106b via the hinge member 107. At the rear of the fallboard, a front panel, not shown, which has approximately the same height as the depth of the fallboard is fixed in a raised position, and when the fallboard is fully opened, the front cover 106a is tilted toward the front panel into a raised position in which it abuts on stoppers 124 formed on respective lateral side panels to be supported thereon.
However, this electronic keyboard instrument is configured such that an upper part of the body of the instrument is covered by the front panel fixed in the raised position, and when the fallboard is in the open or raised position, the fallboard has its uppermost part lying at a level lower than the height of the front panel. That is, the front panel rises high from behind the fallboard, and a topboard mounted on top of the front panel is at a high position. This construction makes the electronic keyboard instrument bulky in the vertical direction, and makes the player feel oppressed when he plays.
To lower the position of the topboard and reduce the height of the front panel or omit the front panel, there have been proposed a construction in which the entire fallboard is supported in a manner slidable in the forward and rearward directions, and when the fallboard is opened, it is moved rearward to be received below the topboard, and a construction in which when the fallboard is in the open position, it is moved rearward to be rolled up. However, neither of these constructions can add a quality appearance of a pivotable fallboard that originates in an acoustic piano to an electronic keyboard instrument. Further, such a fallboard is opened by being pushed under the topboard, not by being raised upward as in the case of the pivotable fallboard, so that it is inferior to the pivotable fallboard in the simplicity and ease of operation.